Dropping frames with fast computer from SVHS source via SVID

[colojim]

I have just built a new computer with P4 3Ghz, 800MHz FSB, 1GB of 400MHz PC3200 RAM dual channel, with video card a Leadtek A310 5600 chip with MyVIVO for video capture, plus SATA 160Gb hard disk and separate 80GHz hard drive (considering installing another and making them RAID).
You would think I have enough power and speed to be able to capture VHS video as AVI with 720x576 resolution for cleaing up and editing in Virtual dub.
But I can't predict nor control the way the recorded image can be jerky and lose synchronization with the sound.
There have been times I have captured with Virtual dub and dropped no frames, other times I am dropping over 10%.
I have turned on DMA, gone through the mother board bios to make sure the settings are favourable for video and still I have these problems.
Also installed a PCI soundcard and disabled the onboard sound chip of the motherboard.
The best filter in Virtual dub for improving the video has been spot remover, but on playback the motion is so jerky with sound even more out of sych. it defeats the purpose.
It surely doesn't have anything to do with the fact that the VHS tapes I am trying to revive are over twenty years old does it? Or am I going to have to buy another card to do capture and compression in the hardware and not with software?
Suggestions much appreciated.

[MrMungus]

I'd suggest you dump analog capture and go digital. You can (a) use an analog > digital converter (like my DVMC-DA2) + firewire input, (b) use a card that records to DV with analog inputs on it (c) use your digital camcorder with firewire output to do analog passthrough or (d) get a card that captures directly to MPEG-2 with analog inputs.

[lordsmurf]

mrmungus, that's not a solution. I don't see why everybody always tries to make somebody buy a new card when that's not the problem.

His method is fine. It's the source.

A TBC may be needed. It sounds like the source is causing the drops.

[Tommyknocker]

And since some of his captures go okay, he may not need a TBC either, even though it is a "nice to have". I would suggest defragging all his hard drives, and shutting down all unnecessary applications during captures. And do nothing on your system while it is capturing.

[MrMungus]

mrmungus, that's not a solution. I don't see why everybody always tries to make somebody buy a new card when that's not the problem.

His method is fine. It's the source.

A TBC may be needed. It sounds like the source is causing the drops.

Hi Smurf. Great website, by the way. I was learning about TBC's over there the other day...but I couldn't email you for some reason...maybe it's my flash killer...

Anyway, yes, I know that saying, "Get some different hardware" is not a good answer and I know for sure you know more about all this than I do, but, having done both analog and digital capture, I don't think I'll ever to back to analog again and my advice is intended to make his life easier, not just to advocate the method I think is better. Digital (e.g., via firewire) capture is just so much better and easier (for me, anyway). For example, I'm capturing VHS to DV AVI via a Sony DVMC-DA2 analog>digital converter on this very computer as I type this and I'm able to do that because the setup I'm using doesn't rely on my processor like analog capture seems to.

I guess I really didn't answer his question...just thought I had a better way that goes around the problem,

[FulciLives]

You will need to do one of two things if not both:

1.) Buy a JVC S-VHS VCR that has a TBC built in
2.) Buy a stand alone TBC such as the DataVideo TBC-1000

Currently there are only two model JVC S-VHS VCR units that have a TBC built-in. The HR-S9911U has a MSRP of $599.95 USD but I've seen it as low as around $350 and it probably is the best one JVC makes. The SR-V10U has a MSRP of $400 but again I've seen it for much cheaper ... generally cheaper than the HR-S9911U but it lacks some of the "nice" features of the more expensive HR-S9911U although many here have reported that it still works well.

If you want more info on these the HR-S9911U can be found on the JVC website under CONSUMER electronics and the SR-V10U is under PROFESSIONAL electronics.

The DataVideo TBC-1000 is a stand alone TBC that can be used with any analog video device. It has composite and S-Video inputs/outputs. It can be bought from a variety of on-line websites for around $300 USD

One such website that has the DataVideo TBC-1000 would be THE ELECTRONIC MAILBOX

Now BOTH would be the BEST way to go but if you only have enough money for one over the other then you will probably get better results with the DataVideo TBC-1000 since the TBC in the JVC S-VHS VCR units is somewhat weak.

HOWERVER ...

According to LORDSMURF the JVC S-VHS TBC does something slightly different than the DataVideo TBC-1000 so it is his opinion that sometimes you need BOTH but this depends on the quality of the source tape and how well the JVC S-VHS VCR tracks it etc.

In short the problems you are having should be correctable with a TBC or TIME BASE CORRECTOR. No amount of computer speed will help here.

One last point I should make. Some capture cards or devices are more prone to frame drop problems with poor quality source material. However even one that drops many frames due to being so sensitive should capture "rock solid" when using a TBC.

- John "FulciLives" Coleman

*** EDIT ***
When I wrote this it would have been the second reply or third in the post count on this THREAD but it took me so damn long to type it up (with a bathroom intermission to boot) that a lot of other people beat me to the punch hehehe

[lordsmurf]

Now BOTH would be the BEST way to go but if you only have enough money for one over the other then you will probably get better results with the DataVideo TBC-1000 since the TBC in the JVC S-VHS VCR units is somewhat weak.

It's unfortunate to have to suggest both, but there are different kinds of TBC's. I hate buying things as much as the next person. But when you deal with video AND expect top quality, it pretty much unavoidable.

The one built into the JVC have DNR circuitry added to them. They are made to remove visual noise, though it can come at the expense of stability of the image. I'd not call it weaker. Just different basis for operation. It can sometime destabilize the image even. It's why any TBC built on this basis should always have an ON and OFF button.

The DataVideo is a "true" TBC by most definitions. It is field corrective. It was not meant to enhance or clean the visuals, just purify the signal itself. Any visual "cleaning" it does is merely a side effect.

Used together, these will give you a visually enhanced picture, with a stable signal to back it up. Best scenario.

Lower "enhancers" (like the SIMA SED-CM) are based upon weak implementations of them both. You get a little of each. These are weak. They do little. But if all you need is a nudge, it'll do in a pinch. Including merely preventing dropped frames.

I'd keep an eye out for a SIMA SED-CM for just dropped frames (as caused from unstable source, as it the case here it seems). You're looking at another $40 for video. Not bad if it works.

[spectroelectro]

Yes, a true full-field frame buffer TBC sounds like the answer. A cheaper possible solution: try playing back the problematic VHS tapes on a different VHS deck. If that doesn't work, then a full standalone TBC is your next best option. The AVT 8710 only costs $179 + shipping, and it's a full-on standalone TBC. Available at http:/avtoolbox/miscvideoproducts.htm
Smurf's suggested brand of TBC also works well but costs $120 more.
BUt try playing the VHS tape back on a high-quality VHS deck with digital tracking first, that might (might, mind you) solve the frame drop problem.

[johns0]

You might be getting more dropped frames if your audio is set to mp3 and not full pcm capture.

[hwoodwar]

Colojim:

Twenty year old tapes could definitely be the problem. That is why some people are mentioning a Time Base Corrector. Three things come to mind that may help:


1. Ram resident programs (basically anything that puts an icon in the bottom right corner) such as Instant Messenger, Virus Scanners, Realplayer, etc... Try using msconfig to temporarily disable them and see if the situation improves.

2. Resolution; The higher the capture resolution the more likelyhood of dropped frames. It makes no sense to capture at 720x576 resolution when the incoming signal from the VHS tape is 480x576 or less. Try lowering the capture resolution.

3. Something that helps me "sometimes" capturing older tapes, is to run the tape for 5-10 minutes and manually adjust the tracking to it's most stable position, without noisebars on the image. Then rewind and start the actual capture.

[colojim]

Thank you for your suggestions folks.
I did an experiment in the weekend where I affixed an antenna to the JVC s-VHS vcr/dvd combo, and fed that in to the computer, capturing full resolution and PCM audio. No dropped frames at all and excellent picture quality, which shows the PC is fine, it is the old tapes that are the problem.

I am looking at installing a Canopus ADVC100 that can feed DV to the PC and lock audio unless anyone has some bad experience with this approach.